EDM machines are capable of high precision manufacturing as well as adding features that would otherwise be very difficult to machine. For example, a sinker can be used to add a blind keyway in the ID of a hardened ring.
We have two wire EDM’s for parts up to 10″ tall. One hole popper that can drill straight holes through most metals with fairly high accuracy and straightness. And one sinker EDM that uses electric pulses to slowly remove material from parts.